This invention relates to an indicator of vehicle service intervals for detecting and displaying the arrival of the time limit at which inspection and reconditioning of a vehicle must be carried out. More particularly, this invention relates to an indicator of the kind above described in which the distance traveled by a vehicle is integrated so as to generate a display signal or to actuate a suitable control means when the total distance traveled by the vehicle attains a predetermined value representing the time limit at which inspection and reconditioning of the vehicle must be carried out.
It is generally necessary to inspect and recondition various parts of a vehicle at a suitable time in order to ensure safe and trouble-free running of the vehicle. This inspection and reconditioning work is desirable for previously detecting such parts which are going to develop trouble or failure before such trouble or failure occurs, and to this end, it is important to inspect and recondition the necessary parts of the vehicle at a predetermined proper time. Commonly, this time is determined on the basis of the distance having been traveled by the vehicle.
According to prior art practice, the distance traveled by a vehicle is displayed only by an odometer and the driver reads the indication of the odomoter to determine the time at which the vehicle must be inspected and reconditioned. Thus, the necessary inspection and reconditioning has not necessarily been carried out at the proper time, and a situation has frequently occurred in which the necessary inspection and reconditioning is carried out at a time considerably later than the proper time especially for such a reason that the driver forgets to read the indication of the odometer. Failure to carry out the necessary inspection and reconditioning at the proper time means that the vehicle continues to run in a dangerous state, and this tends to increase the rate of occurrence of accidents. Thus, such failure has tended to provide a very great social problem. In recent years, vehicles are obligated to equip an exhaust gas recirculating device, a catalytic converter or the like for preventing pollution of the atmosphere. These exhaust gas purifiers must be inspected or the catalyzer must be replaced by a fresh one after the vehicles have run a suitable distance.